Dynamic identification of a concrete bridge with orthotropic plate-type deck

This paper continues a line of research aimed at the development of a dynamically-based health condition monitoring of bridge structures in the area of Friuli Venezia Giulia, Italy. One subject of this research program has been a two-span highway bridge with concrete slab supported by closely spaced precast beams, a constructive typology which is quite diffuse in the regional highway network. Forced-vibration tests and experimental modal analysis were used to determine the vibration properties of the structure. An identification procedure based on dynamic data allowed to define an accurate orthotropic plate model of the deck and to improve the description of some constructional details in the finite-element model of the bridge, such as the boundary conditions on abutments and the connection between deck and pier. The usefulness of the combined experimental and analytical process in identification of structural properties has been proven, and the procedure can be applied to other structures of the same typology.